Residue handling system for an agricultural combine

ABSTRACT

A residue handling system for an agricultural combine including a residue chopper that provides enhanced air flow for evenly distributing crop materials onto a crop field. A hub and blade assembly accurately positions flail blades and resists fatigue stresses. Each flail blade includes an outer portion that is angled longitudinally away from a plane transverse to the axis of rotation. In a mated blade pair embodiment, the leading edges of the paired flail blades may be closer to each other than the trailing edges, or vice versa. Also, the leading edges of the flail blade pair may be the same distance away as the trailing edges of the pair, beneficially directing discharge sideways in a preferred common direction. The assembly includes a mounting support post that has a width substantially equal to the distance between two mated blades. The mated blades are installed directly against the sides of the mounting support, without spacer bushings, using only three connector elements.

FIELD OF THE INVENTION

[0001] This invention relates generally to an agricultural combine. Itrelates particularly to a residue handling system for an agriculturalcombine.

BACKGROUND OF THE INVENTION

[0002] Agricultural combines are well-known machines for harvesting cropmaterials. They are available in various forms but all perform the basicfunctions of reaping crop materials from a field, separating grain fromnon-grain crop materials, and discarding the non-grain materials in thefield.

[0003] A typical combine includes a crop harvesting or header assemblywhich reaps ripened crop plants from the crop field and a feederassembly which feeds the crop materials to a threshing assembly. Onetype of combine incorporates a rotary threshing assembly. In such acombine, the crop materials are introduced to the front end of therotary threshing assembly, which is oriented longitudinally, or axially,within the combine body. The crop materials are then threshed between arotating rotor, which includes rasp bars along its exterior, and theinside of a rotor cylinder. Along the bottom of the rotor cylinderconcaves are mounted that allow grain heads and other fine materials topass through while retaining the crop stalks within the rotor cylinder.

[0004] The rotary threshing assembly includes mechanisms for feeding thecrop materials rearwardly through the rotor assembly so that the cropstalks and other materials which do not pass through the concaves aredischarged out the rear end of the assembly. The grain heads and otherfine materials pass through the concaves onto a series of sieves thatseparate the grain from the unwanted fine materials. A cleaning fandirects air flow through the sieves to assist in the separationoperation. After separation, the grain is conveyed to a grain binthrough an auger system and the unwanted fine materials are dischargedfrom the rear end of the sieves.

[0005] Modern farming practices require that the unwanted crop stalks bechopped up, mixed with fine materials, and evenly spread across the cropfield. This is especially true with no-till farming, but is alsoimportant for more traditional farming techniques.

[0006] The demand for greater productivity has resulted in larger headerassemblies, which harvest wider swaths in the crop field, and increasedtravelling speeds of the combine across the crop field. This has led toa need for more effective distribution systems for the non-grain cropmaterials.

[0007] A common type of non-grain or residue distribution systemincludes a residue chopper. The residue chopper is typically located inthe rear of the combine body. Some types of residue choppers receive anddistribute only crop stalks from the rotor assembly. Other types receiveand distribute both crop stalks and fine materials from the sieves.

[0008] The residue chopper is oriented transversely of the combine andincludes a plurality of flail blades which chop and mix the cropmaterials. The flail blades are pivotally connected to supports on arotating hub. Normally, two flail blades are attached to each support,with one on each side of the support. In most prior art systems the twoflail blades are spaced from the mounting support with spacer bushings.However, with such a construction, the mounting flange can become weakfrom continuously applied stresses and eventually break, causingunwanted downtime and repair costs. Additionally, use of these spacerbushings does not permit accurate positioning of the flail blades.

[0009] Air flow through the residue chopper greatly influences theeffectiveness of the chopper in mixing the crop materials anddistributing them from the rear of the combine. Vanes located at theexit of the residue chopper sweep in an outward direction to spread thecrop materials across the crop field. Optimally, the crop materials willbe discharged evenly in a swath which is the same width as the combineheader assembly. However, because combine header assemblies can be aswide as thirty feet and more, the crop materials must exit the residuechopper at a high velocity in order to be directed across a wide swath.This necessitates a large volume of air flow through the residue chopperto achieve the desired exit velocity.

[0010] In residue choppers which receive both crop materials from thethreshing assembly cylinder and fine materials from the sieves, it is acommon practice to direct the cleaning fan air through the residuechopper. In this arrangement, the residue chopper housing becomes theprimary path for the cleaning air, and the cleaning fan becomes theprimary source of air flow through the residue chopper. The design andshape of the residue chopper's flail blades is important in ensuringadequate air flow through the chopper. Some known flail blades inhibitair flow through the residue chopper and actually create back pressurethat partially prevents the cleaning fan air flow from entering thechopper. This not only adversely affects exit velocity of the cropmaterials but also reduces the effectiveness of the cleaning fan inseparating the grain from the non-grain fine and light materials.

BRIEF SUMMARY OF THE INVENTION

[0011] It is a primary object of the invention to provide an improvedresidue chopper in a rotary combine.

[0012] It is also an object of the invention to provide an improvedflail blade which assists the cleaning fan in moving air through theresidue chopper.

[0013] It is another object to provide an improved flail blade whichincreases air flow through a residue chopper.

[0014] It is still another object to provide a flail blade which isconfigured intermediate its ends so that the front surface of the bladeis inclined from the direction of blade travel in the chopper.

[0015] It is a further object of the invention to provide a mountingarrangement for the flail blades on a hub which includes a hollowmounting support having a width equal to the desired space between theinner ends of mated flail blades.

[0016] It is still a further object to provide a flail blade mountingarrangement which better resists fatigue stresses while providing moreaccurate flail blade positioning.

[0017] It is yet a further object to provide an improved hub and bladeassembly in a residue chopper for a rotary combine.

[0018] It is yet another object to provide an improved hub and flailblade assembly including a pattern of flail blades which providesoptimum residue distribution.

[0019] According to the invention, each flail blade is pivotallyconnected to a rotatable hub in a hub and blade assembly. An innerportion of the flail blade is flat and lies in a plane perpendicular tothe axis of rotation of the hub. An outer portion of the blade is alsoflat, but is inclined from that plane. Thus, the front surface of theouter portion of the blade is inclined at an angle to the plane ofrotation of the blade. As the blade rotates during operation of thechopper, this angled front surface increases the flow of air through thechopper housing by moving air ahead of it.

[0020] In a mated blade arrangement, two blades are attached to a singlemounting support. In a first form of mated blade arrangement, the outerportions of the blades are angled in opposite directions so that theleading edges of the outer portions of two flail blades are closer toeach other than the trailing edges. What amounts to a V-shaped pocket isformed behind the blades as they rotate. In a second form of mated bladearrangement, the trailing edges of the outer portions of mated bladesare closer to each other than the trailing edges, creating a V-shapedpocket in front of the blades. In a third form of mated bladearrangement, the leading and trailing edges are equidistant from eachother. A fixed knife attached to the housing passes between the leadingedges of the mated blades when the hub rotates, producing a scissorscutting action to chop-up crop materials.

[0021] According to the invention, different forms of mated bladearrangements may be mounted on the same hub to create a pattern in thehub and blade assembly which produces a desired pattern of residue blownfrom the chopper. A hub and blade assembly may be effectively dividedinto three sections: a center section having the first and/or secondform of blade arrangements thereon; a left section having the third formof blade arrangements thereon with the outer blade portions inclined soas to direct residue to the left as well as rearwardly; and, a rightsection having the third form of blade arrangements thereon with outerblade portions inclined so as to direct residue to the right as well asrearwardly.

[0022] The mounting support for each blade or mated pair of bladesincludes a rectangular cross-section post. The mounting support post hasfront, back, and side walls. The width of the post is substantially thesame as the desired distance between the parallel inner portions of twomated flail blades. Therefore, the side surfaces of the inner portionson the flail blades directly contact the side walls of the mountingsupport post, without the need for spacer bushings. The flail blades canbe pivotally mounted on the support post using only three mountingelements and a wrench.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

[0023] The invention, including its construction and method ofoperation, is illustrated more or less diagrammatically in the drawings,in which:

[0024]FIG. 1 is a side elevational view of a portion of a rotaryagricultural combine, with parts of the combine removed to displayinternal components;

[0025]FIG. 2 is a vertical sectional view through a straw chopperembodying features of the invention;

[0026]FIG. 3 is a perspective view of a portion of the hub and bladeassembly in the straw chopper of FIG. 2;

[0027]FIG. 4 is a side elevational view of the hub and blade assemblythe straw chopper of FIG. 2 with parts removed;

[0028]FIG. 5 is front elevational view of the hub and blade assemblyseen in FIG. 4;

[0029]FIG. 6 is an exploded view of the blade mounting elements for theblades seen in FIGS. 4 and 5;

[0030]FIG. 7 is a front elevational view of a second form of hub andblade assembly for the straw chopper;

[0031]FIG. 8 is a front elevational view of a third form of hub andblade assembly for the straw chopper; and

[0032]FIG. 9 is a top plan view of a modified hub and blade assembly forthe straw chopper of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0033] Referring to the drawings, and particularly to FIG. 1, a portionof a rotary combine is shown generally at 10. The combine portions 10includes a feeder assembly 20 and a rotary threshing assembly 22. Therotary threshing assembly 22 includes a rotor 26 and a rotor housing 28.Crop materials travel rearwardly through the rotary threshing assembly22 and are threshed by a series of threshing elements attached to theexterior of the rotor 26.

[0034] Along the bottom side of the rotor housing 28 are perforatedconcaves 30 which allow grain heads and other fine materials to passthrough, and out of, the rotary threshing assembly 22. Larger materialpieces such as crop stalks continue rearwardly through and aredischarged out the rear end of the rotary threshing assembly 22.

[0035] The grain heads and other fine materials are directed to a seriesof sieves 32. A drive mechanism (not shown) effects a constant back andforth motion between the sieves 32. As the crop materials pass throughthe sieves 32, they further separate the grain from the unwanted chaffand fine and light materials. A cleaning fan 34 located forward of thesieves 32 blows air rearwardly through the sieves, thus helping toseparate the grain from the fine and light materials. The cleaning fan34 air also drives the unwanted fine and light materials out the rearend of the sieves 32.

[0036] The distribution of unwanted crop materials onto the clearedfield as the combine 10 travels across the field is effected by aresidue chopper 41 embodying features of the invention. The chopper 41chops the crop stalks into a finer residue material, mixes the choppedcrop stalks with the chaff fine materials, and distributes the mixedresidue evenly across the crop field. The residue chopper 41 is orientedtransversely of the combine to the rear of the threshing assembly 22.

[0037] Referring now to FIG. 2, the residue chopper 41 includes housing42 mounted in the combine body 12 and elongated transversely of thebody. The housing 42 encloses a rotatable hub and blade assembly 49,including a hub 48 to which flail blades 50 are pivotally attached,preferably in mated pairs. The hub and blade assembly 49 is viewed fromone end in FIG. 2, which shows it rotating in a counter-clockwisedirection.

[0038] The housing 42 has front entrance 44 through which both cropstalks and chaff fine materials enter. It also has a rear exit 46 wherechopped materials exit. To aid in spreading the exiting crop materialsevenly across the field, vanes 47 are attached to the rear end of thecombine body 12 near the rear exit 46. The vanes 47 are angled outwardlyso that the crop materials which exit the system 40 are redirected tocover a wide swath pattern. Optimally, the width of the swath pattern isequal to the width of the header assembly 18.

[0039] To spread the crop materials over a swath of this width, the cropmaterials have to contact the vanes 47 at a high velocity. In order toachieve this high velocity, a large amount of air flow must be driven ata high speed through the housing 42. The system 40 of the presentinvention accelerates the stream of air received from the cleaning fan34 so as to produce an air flow speed of up to sixty miles per hour atthe exit 46.

[0040] Referring now to FIG. 3, in the hub assembly 49 a plurality offlail blades 50 are pivotally attached to a hub 48 in pairs 51, arrangedin a row spaced along the length of the hub 48. In turn, four such rowsare displaced 90° from each other around the hub 48. Drive means (notshown), which are well known to those skilled in the art, rotate theassembly 49.

[0041] Referring additionally to FIGS. 4 and 5, each flail blade 50includes a flat inner mounting portion 54 lying in the plane of bladerotation, which is transverse to the axis of the hub 48. The outerportion 56 of the flail blade 50 is angled away from the plane ofrotation of the blade. The blades 50 are pivotally connected to the hub48 in a manner hereinafter discussed.

[0042] A preferred method of manufacturing the flail blade 50 is bybending a single piece of metal so that an intermediate portion 58 isbent in a smooth transition between the outer portion 56 and the innerportion 54. In the illustrated blade, 50, the outer portion 56 is flat,both longitudinally and transversely. Therefore, as the hub 48 rotateseach radial line along its forward surface 60 travels along a differentplane.

[0043] Although the invention envisions employing a variety of blade 50angles, a preferred configuration has a flat outer portion 56 which isangled five degrees from the plane of blade rotation so that itsprojected frontal area is twelve millimeters wide. In an alternativeconfiguration, the flat outer portion 56 is angled thirty-five degreesfrom the plane of blade rotation so that its projected frontal area istwenty-four millimeters wide. The specific angle of the outer portion 56in a flail blade can be tailored to optimize the cutting action, i.e.fine or coarse, and the effect on exiting air flow velocity of thesystem 40.

[0044] The flail blades 50 are preferably attached to the hub 48 inmated pairs 51, as has been pointed out. In the arrangement seen inFIGS. 3-5, the leading edges 62 of the outer portions 56 on mated flailblades are relatively close to each other. The trailing edges 64 of theouter portions 56 on the mated blades, on the other hand, are relativelyfurther from each other. A V-shape pocket is formed between, and behind,the outer portions 56 of the mated blades.

[0045] As the hub 48 rotates, the forward surfaces 60 of the outerportions 56 compress the air in front of the blades 50, driving airforward. Also, a pressure drop is created in the pocket formed behindthe rear surfaces 61 of the outer portions 56 of each pair of blades 50,causing the rotating blades to draw air from the rear.

[0046] Referring to FIG. 2, attached to the base of the housing 42, infixed relationship, are a series of knives 43 (only one shown). Theknives 43 extend upwardly, inside the housing 42, between mated pairs offlail blades 50. A scissor-like cutting action results as each flailblade 50 passes by a knife 43. The cutting action chops the cropmaterials into a finer residue.

[0047] The knife blades 43 are all mounted in one, downwardly removablecassette 70. The number of knife blades 43, and their placement, canthen be easily changed, based on the angle and width of the flail blades50, in order to achieve a variety of fine or coarse cutting actions.

[0048] Preferably, the leading edge 62 of each blade 43 is sharpened, asat 63, to enhance the scissor action. This is accomplished by relievingthe leading edge 62 to a surface that it lies in the plane of blade 50rotation, or is angled from this plane, so that this surface actuallyundercuts the forward surface 60.

[0049] The blade 50 mounting support includes a mounting post 72 foreach pair of blades 50 fixed to the hub 48. Each post 72 comprises arectangular cross-section tube extending radially away from the hub 48.Each tube includes front and back walls 74 and 75, and left and rightside walls 76 and 77. The outside width of the tube in each mountingpost 72 is substantially the same as the desired distance between themounting surfaces 52 of a mated pair of flail blades 50. Thus, themounting surfaces 52 of the flail blades 50 seat flush against theexterior surfaces of the side walls 76 and 77.

[0050] Referring to FIG. 6, as well as FIG. 5, the mated pair of blades50 are pivotally mounted on the support post 72 with a hollow pin 78.The pin 78 extends through the inner portions 54 of the flail blades 50and the mounting support side walls 76 and 77. The pin 78 has a cap 79at one end and an internally threaded bore 80 extending into the otherend. A bolt 81 having a head 82 and a threaded shaft 83 is insertedthrough a washer 84 into the bore 80. The threaded shaft 83 is receivedin the threaded bore 80. The bolt 81 can easily be tightened with awrench, acting on the head 82.

[0051] In order to provide maximum contact area between the flail blade50 and the mounting support 72, and to allow pivoting clearance betweenthe inner portion 54 of the flail blade and the hub 48, the innermostedge of the flail blade is formed in a segmentally circular shape aroundthe pivot axis of the bolt 78. This is best seen in FIG. 4.

[0052] The flail blades 50 are more accurately positioned in the presentinvention because spacer bushings, which are commonly used in prior artsystems, are not required. Additionally, a greater area of surfacecontact and, thus, support is possible between the flail blade mountingsurface and the mounting support side walls 76 and 77. Because the flailblades are positioned more accurately, a more effective scissor actionis made possible because each knife 43 may be positioned closer to thespaced flail blades 50 than is possible with prior art mounting systems.The tubular configuration of the mounting post 72 is also stronger thanthe simple tang mounts prevalent in the prior art. Therefore, themounting post 72 can better resist fatigue stresses, stresses that causetang mounts to break.

[0053] In the first form of blade assembly 49 which has been described,the leading edges 62 of mated blades 50 are relatively close to eachother while the trailing edges 64 are relatively further apart. In asecond form of blade assembly, seen in FIG. 7, just the opposite istrue. In this form, the trailing edges 164 of mated blades 150 arerelatively close to each other while the leading edges 162 arerelatively further apart.

[0054] In a third form of hub and blade assembly 249 embodying featuresof the present invention, as seen in FIG. 8, the leading edges 262 andtrailing edges 264 of the mated blades 250 are equidistant from eachother. The outer portions 256 of each blade 250 in a mated pair areangled at anywhere between five degrees and thirty-five degrees from aplane transverse to the axis of rotation of the hub 248.

[0055] Referring now to FIG. 9, another hub and blade assembly 349embodying features of the invention is illustrated. The assembly 349utilizes a combination of blade forms which produce a particularlyadvantageous result; serving both to enhance air flow through thechopper housing and the spreading of exiting crop materials across thefield.

[0056] As seen in FIG. 9, the hub and blade assembly 349 includes a hub348. Six rows of mated pairs 351 of blades 350 are mounted on the hub348 (60° displayed from each other). Each row contains five evenlyspaced pairs 351 of blades 350.

[0057] Each row of blade pairs 351 also includes three different blade350 arrangements, 350A, 350B and 350C. In FIG. 9 in the uppermost bladerow illustrated, each blade pair 351A is constructed and arrangedaccording to the first form of the invention. The blade pair 351B isconstructed and arranged according to one variation of the third form ofthe invention. Each blade pair 351C is constructed and arrangedaccording to another variation of the third form of the invention.

[0058] Insofar as variations of the third form of blade pairs 351B and351C are concerned, it will be seen that the variation resides in thedirection of inclination of the outer portions 356 of the blades 350 inquestion. The blades 350 in the pairs 351B have both outer bladeportions 356 inclined (in the same direction) so as to drive air axiallyoutwardly of the hub 38, as well as rearwardly. Similarly, the blades 30in the pairs 31C have outer blade portions 356 inclined (in the samedirection) so as to drive air axially outwardly, as well as rearwardly.

[0059] Each row-of blade pairs 351 has at least one, and sometimes asmany as three, pairs 351A (the pairs 351 are staggered in differentrows). Each has, in addition, at least one pair 351 each of 350B and350C blade configurations. The effect of this construction is to effecta powerful rearward and laterally outward flow of air from the system40. Spreading of crop material is further enhanced by this arrangement.

[0060] While a preferred embodiment of the invention has been described,it should be understood that the invention is not so limited, andmodifications may be made without departing from the invention. Thescope of the invention is defined by the appended claims, and alldevices that come within the meaning of the claims, either literally orby equivalence, are intended to be embraced therein.

1. In a residue handling system for an agricultural combine, theimprovement in a residue chopper, comprising: a) a housing having aninlet and an outlet, and a hub and blade assembly rotatable in saidhousing; b) said hub and blade assembly including a hub housing a postextending radially therefrom and rotatable with said hub in a plane ofrotation; and c) a chopper blade including an outer blade portion havinga face that is inclined at an angle to said plane of rotation and aninner portion which lies in said plane; d) said inner portion seated inflush, sliding relationship against one side of said post.
 2. Theimprovement in a residue chopper of claim 1 further characterized inthat: a) said hub is adapted to rotate in one direction and said outerportion of said blade has a leading edge and a trailing edge relative tosaid one direction of rotation.
 3. The improvement in a residue chopperof claim 2 further characterized in that: a) said leading edge issharpened by being relieved on at least one side to form a surface whichalso lies approximately in said plane.
 4. In a residue handling systemfor an agricultural combine, the improvement in a residue chopper,comprising: a) a housing having an inlet and an outlet, and a hub andblade assembly rotatable in said housing; b) said hub and blade assemblyincluding a hub having a mounting element extending radially therefromand adapted to rotate in a plane perpendicular to said hub; c) a pair ofchopper blades, each of said blades including an inner portion pivotallyconnected to said mounting element and an outer portion extendingradially away from said hub; d) said outer portion of each of saidblades including a front face and a rear face extending substantiallyparallel to each other and lying at an angle to said plane; and e) eachof said blades has a leading edge and a trailing edge on its outerportion when said assembly is rotated;
 5. The residue chopper of claim 4further characterized in that: a) said leading edges of said outerportions in said pair of blades are closer together than said trailingedges.
 6. The residue chopper of claim 4 further characterized in that:a) said trailing edges of said outer portions in said pair of blades arecloser together than said leading edges.
 7. The residue chopper of claim4 further characterized in that: a) said leading edges and said trailingedges of said outer portions in said pair of blades are substantiallyequidistant from each other.
 8. The residue chopper of claim 4 furthercharacterized in that: a) said mounting element comprises a post havingparallel side walls with flat outer surfaces; b) said inner portion ofeach of said blades being mounted flush against a corresponding flatouter surface of said post.
 9. The residue chopper of claim 8 furthercharacterized in that: a) said inner portions of each of said bladesbeing retained flush against a corresponding flat outer surface of saidpost in sliding relationship therewith by one mounting pin and boltassembly.
 10. The residue chopper of claim 9 further characterized inthat: a) said mounting pin has an internally threaded bore at one end,said bolt being threaded into said bore.
 11. The residue chopper ofclaim 9 further characterized in that: a) said mounting pin and boltassembly also includes a washer.
 12. The residue chopper of claim 4further characterized by and including: a) a knife assembly removablymounted in said housing; b) said knife assembly including a knifeextending readially inwardly toward said hub between said chopperblades.
 13. The residue chopper of claim 12 further characterized inthat: a) at least one of said edges of at least one of said outer bladeportions cooperates with said knife in scissors-like relationship duringchopper operation.
 14. In a residue chopper for a combine's residuehandling system, a hub and blade assembly comprising: a) a horizontallyelongated hub extending transversely through a housing having a frontinlet and a rear outlet for a stream of air containing entrainedresidue; b) a plurality of mounting posts mounted on said hub andextending radially therefrom at predetermined intervals along the lengthof said hub, each of said hubs adapted to rotate in a separate plane; c)a pair of chopper blades mounted on each of said posts, each of saidpair including an inner portion pivotally connected to a correspondingpost and an outer portion extending radially away from said hub; d) saidouter portions of each blade in each pair of blades including a frontface and a rear face extending substantially parallel to each other andlying at an angle to said plane of a corresponding post; e) each of saidblades having a leading edge and a trailing edge on said outer potionwhen said hub is rotated.
 15. The hub and blade assembly of claim 14further characterized in that: a) on at least one of said posts saidcorresponding pair of blades has leading edges of its outer portionswhich are closer together than its trailing edges; b) on at least oneother of said posts said corresponding pair of blades has leading edgesof its outer portions which are substantially equidistant from eachother.